08 · Robbery · Robbery system

LTD Safe Robbery

A robbery for the convenience stores that players own. A small safe sits in the store's back room: you crack its 6-digit combination on a dial while a 5-minute timer runs and the police have already been alerted. The money isn't created out of nothing. It comes out of that store company's real account, so the robber's gain is the owners' loss.

Role: Lua (client + server), NUI
Server: Skyland
Framework: ESX
Stack: Lua, ESX, esx_addonaccount, ox_lib, oxmysql / MariaDB, NUI, tk_dispatch
Target: Player-owned LTD stores
Status: Live on Skyland

The safe in the back room of the Mirror Park LTD, with the prompt to press E — The safe in the back room of the Mirror Park LTD: walk up and press E to start cracking it 1 / 5

The safe screen listening to the mechanism: two discs found, the dial on 7 and a stethoscope pulsing — The safe in the back room of the Mirror Park LTD: walk up and press E to start cracking it 1 / 5

6 digits in the combination, generated and kept on the server
5 min to open the safe
5 h cooldown after a success, stored in SQL
78 offline checks on the decision logic

How it works

Start to finish

Cracking the safe: two discs found, and the third is higher than 5, so only 6 to 9 are left on the dial 3 / 5
01 — The dial

Higher, lower or click
- The combination never leaves the server. The client can only send three things: start, try this digit, cancel. It gets back higher, lower or click, and there's no "I finished" message to fake: the safe opens when the server has counted six correct digits.
- The server does the waiting too: each try takes two seconds on its side before the answer comes back, so the delay can't be skipped or stacked, and the 5-minute limit is checked before and after every try.
- The safe screen is a NUI built for it: a 10-notch dial, lock discs that turn green, a flip-clock timer, and a hint showing the range your tries have already narrowed down. It was picked from three prototypes.
Six clicks and the door swings open: 243,158 $ taken straight from the store's company account 4 / 5
02 — The money

Paid from a real account
- The amount is rolled at the start (100,000 to 300,000 $) and capped by what the company holds when the safe opens; under 100,000 $ the safe counts as empty. Nothing moves before success, so a crash or a restart can't lose or duplicate money.
- Police get a dispatch alert the moment it starts, with the store and the street. Police and the store's own employees can't rob it, and a minimum number of officers online is checked server-side.
- Every attempt is logged: an SQL row with the player, the store, the amount rolled and paid, the company balance before and after, timings and outcome, plus Discord embeds (retried when Discord rate-limits) and a line in the company's transaction history.
After a robbery the safe stays locked for five hours, with a live countdown right on the prompt 5 / 5
03 — Lockouts

Cooldowns that survive restarts
- A 5-hour cooldown after a success, stored in SQL so it survives restarts.
- A failed attempt locks the safe and the robber for 10 minutes and changes the combination. If the server restarts mid-robbery, the attempt is closed at the next boot and the safe is locked.
- One robber per safe and one robbery per player, start requests rate-limited, distance checked on the server at the start and on every try; disconnecting or walking away ends the attempt.

Under the hood

What keeps it solid

Admin tools

Place, turn and nudge a safe in game without a restart, reset it, and read the combination from the server console only.
Each store's safe is switched on in the config, so the rollout goes one store at a time.

Testing

The decision logic is plain Lua tested outside FiveM (78 checks).
The feature was run scenario by scenario on the dev server: success, timeout, wrong digits, key spam, disconnect, restart and every refusal.

Tech